In a virtualized environment, a large number of virtual machines can operate on a single physical host. Many customers elect to use virtual machines for their data computing needs due to the various advantages that a virtualized environment can offer over a non-virtualized environment, such as greater availability, lower costs, and simpler upgrades. When a virtual machine is created, the physical host allocates resources such as central processing units (CPUs) and memory to the virtual machine. For disk space, the virtual machine may use the storage resources of a storage provider that is different from the physical host that provides CPU and memory resources to the virtual machine. For example, the data generated and used by the virtual machine may be stored in volumes managed by a storage controller, such as a filer that operates on a separate machine than the physical host of the virtual machine and uses software provided by a different vendor than the vendor of the virtualization software.
A performance issue originating in the storage environment, such as a problem affecting a particular volume or a storage controller that manages the particular volume, can affect the performance of the virtual machine that utilizes the particular volume. However, in other cases the poor performance of a virtual machine can be attributed to a different source; for example, the problem may be specific to the virtual machine itself, to the communication network used by the virtual machine, the underlying physical host, or some other entity. Many times it is difficult for customers to pinpoint the source of the problem. Better approaches for presenting information to assist a customer in diagnosing the source of a problem that affects a virtual machine are needed.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.